TWI414006B - Formation of in-situ phosphorus doped epitaxial layer containing silicon and carbon - Google Patents

Abstract

Methods for formation epitaxial layers containing silicon and carbon doped with phosphorus are disclosed. The pressure is maintained equal to or above 100 torr during deposition. The methods result in the formation of a film including substitutional carbon. Specific embodiments pertain to the formation and treatment of epitaxial layers in semiconductor devices, for example, Metal Oxide Semiconductor Field Effect Transistor (MOSFET) devices.

Description

In-situ formation method of phosphorus-doped epitaxial layer containing germanium and carbon

Embodiments of the present invention relate to in-situ formation of a phosphorus-doped epitaxial layer comprising germanium and carbon, a specific embodiment relating to, for example, a Metal Oxide Semiconductor Field Effect Transistor (MOSFET). Such an epitaxial layer is formed in a semiconductor element of the type.

The amount of current flowing through the channel of the MOS transistor is directly proportional to the mobility of the carrier in the channel. The use of a high mobility MOS transistor allows more current to flow and results in faster circuit performance. . The mobility of the carrier in the channel of the MOS transistor can be increased by generating mechanical stress in the channel. The channel in compressive strain (e.g., the channel layer grown on the crucible) has a greatly enhanced hole mobility to provide a pMOS transistor. A channel in tensile strain (e.g., a thin channel layer grown on a relaxed crucible) can achieve a greatly enhanced electron mobility to provide an nMOS transistor.

The nMOS transistor channel under tensile strain can also be provided by forming one or more layers of carbon doped germanium epitaxial layers, which are complementary to the compressive strained SiGe channels in the pMOS transistor. Therefore, carbon doped germanium and germanium epitaxial layers can be deposited on the source/drain of the nMOS and pMOS transistors, respectively. The source and drain regions can be flat or recessed by selective Si dry etching. When properly fabricated, the nMOS source and drain covered with carbon-doped germanium epitaxial will apply tensile strain to the channel and increase the nMOS drive current.

In order to achieve enhanced electron mobility in a channel of a nMOS transistor having a recessed source/drain using carbon-doped germanium epitaxy, it is desirable to form on the source/drain by selective deposition or post-deposition treatment. Carbon doped erbium epitaxial layer. Furthermore, it is also desirable for the carbon-doped germanium epitaxial layer to contain a substituted C atom to induce tensile strain in the channel. A higher channel tensile strain can be achieved by having a higher substitution C content in the carbon-doped germanium source/drain.

In general, CMOS (complementary MOS) components below 100 nm (sub-100 nm) require a junction depth of less than 30 nm. Epitaxial layers of germanium-containing materials (eg, Si, SiGe, and SiC) are typically formed in the junctions using selective epitaxial deposition. Selective epitaxial deposition allows the epitaxial layer to grow on the silicon moat rather than on the dielectric region. Selective epitaxy can be used in semiconductor devices, for example as a high source/drain, source/drain extension, contact plug or base layer deposition of bipolar elements.

Typical selective epitaxial processes include deposition reactions and etching reactions. In the deposition process, an epitaxial layer is formed on the surface of the single crystal, and a polycrystalline layer is deposited on at least the second layer (for example, an existing polycrystalline layer and/or an amorphous layer). The deposition reaction and the etching reaction can occur simultaneously, and have relatively different reaction rates for the epitaxial layer and the polycrystalline layer. However, the deposited polycrystalline layer is typically etched at a faster rate than the epitaxial layer. Thus, by varying the concentration of the etchant gas, the net result of the selective process is the deposition of epitaxial material and the deposition of limited (or no) polycrystalline material. For example, a selective epitaxial process can result in an epitaxial layer of germanium-containing material being formed on the surface of the single crystal germanium without depositing on the spacer.

Selective epitaxial deposition of germanium-containing materials is a useful technique in the formation of high-level source/drain and source/drain extension features, for example, in germanium-containing MOSFETs During the formation of the transistor) component. The source/drain extension feature is fabricated by etching the tantalum surface to form a recessed source/drain feature and then by selectively growing an epitaxial layer (eg, [SiGe] material) To fill the etched surface. Selective epitaxy allows near-complete dopant activation with in-situ doping, so post-annealing can be omitted. Therefore, the junction depth can be precisely defined by germanium etching and selective epitaxy. On the other hand, an ultra-shallow source/drain junction will inevitably result in an increase in series power. In addition, the junction consumption during the formation of the telluride will increase the series power. To compensate for junction wear, the raised source/drain is epitaxially and selectively grown on the junction. Generally, the raised source/drain layer is undoped germanium.

During the deposition of the germanium containing layer, the deposition gas may include an elemental dopant source (e.g., boron, arsenic, phosphorus, gallium, or aluminum), thereby causing in situ doping of the epitaxial layer. The dopant system provides a deposited ruthenium containing compound with a variety of conductive properties, such as directional electron flow in a controlled and desired path required for the electronic component.

Current selective epitaxial processes typically require high reaction temperatures, such as about 800 ° C, 1000 ° C or higher, which are typically undesirable for the manufacturing process due to thermal budget considerations and may occur on the substrate. Uncontrolled nitridation of the surface. In addition, at higher process temperatures, most of the C atoms incorporated by the general selective Si:C epitaxial process will occupy Si. The unsubstituted (ie, void) portion of the crystal lattice. By lowering the growth temperature, a higher fraction of the substituted carbon layer can be achieved (for example, close to 100% at a growth temperature of 550 ° C), however, the slow growth rate at this low temperature is not for the component application. Desirably, such selective treatment is not possible at lower temperatures. Furthermore, the Si:C film doped with phosphorus has a lower growth rate.

Therefore, there is a need for a process for epitaxial deposition of germanium and germanium containing compounds accompanied by dopants such as phosphorus. Further, the process should have a rapid deposition rate, maintain process temperature (e.g., about 800 ° C or less, and preferably 700 ° C or less), and have a high substitution carbon concentration. This method can be used in the manufacture of transistor elements.

One embodiment of the invention is directed to a method of forming and processing an epitaxial layer comprising tantalum, carbon, and phosphorus. Other embodiments are directed to methods of making a transistor element comprising an epitaxial layer comprising tantalum, carbon, and phosphorus. According to an embodiment of the invention, the substituted carbon content in the Si:C film is increased. In one or more embodiments, epitaxial growth and etchant activity also increase as the pressure during deposition increases to at least about 100 Torr.

According to an embodiment of the present invention, there is provided a method for forming an epitaxial layer containing tantalum and carbon on a substrate, the method comprising: placing a substrate in a process chamber; and exposing the substrate to a stack The source, carbon source, and phosphorus source, while maintaining the pressure in the process chamber at least about 100 Torr, form a Si:C epitaxial film doped with phosphorus on at least a portion of the substrate. In some embodiments, the pressure system in the process chamber is maintained at at least about 200 Torr. In a particular embodiment, the pressure system is maintained at about 300 Torr. In one embodiment, the temperature in the process chamber is less than or equal to about 700 °C. In accordance with one or more embodiments, the epitaxial film formed contains a substitutional carbon that is at least about 40% (e.g., 50%) of the total carbon contained in the film. In some embodiments, the phosphorus source comprises phosphine, and the concentration of phosphorus in the epitaxial film is at least about 10 ²⁰ atoms per cubic centimeter (atoms/cm ³ ).

According to some embodiments, the substrate comprises a single crystal surface and at least a second surface, the second surface being selected from the group consisting of an amorphous surface, a polycrystalline surface and a composition thereof, wherein the epitaxial layer is formed on the surface of the single crystal, amorphous Or a polycrystalline layer is formed on the second surface. In one or more embodiments, the substrate can be further processed by exposing the substrate to an etch gas. According to one or more embodiments, the etching gas may include HCl, and the step of exposing to the etching gas occurs at a temperature of less than about 700 °C.

In one or more embodiments, a method of forming an epitaxial layer comprising tantalum and carbon on a substrate, the method comprising: placing a substrate in a process chamber, the substrate comprising a single crystal surface And at least a second surface selected from the group consisting of an amorphous surface, a polycrystalline surface, and a composition thereof; and exposing the substrate to a source of germanium, a source of carbon, a source of phosphorus, and an etch source, and simultaneously applying pressure in the process chamber Maintaining at least about 100 Torr (e.g., greater than about 200 Torr) to form a phosphorous-doped ruthenium epitaxial film on the surface of the single crystal without growing on the second surface. In one or more embodiments, the second surface includes a dielectric surface.

The process of the present invention can be used as a manufacturing step of a transistor process. Accordingly, embodiments of the present invention are directed to a method of fabricating a transistor, the method package The method comprises: forming a gate dielectric layer on a substrate in a process chamber; forming a gate electrode on the gate dielectric layer; forming a source on the opposite side of the gate electrode on the substrate / drain region, and define a channel region between the source/drain regions; and deposit an epitaxial film directly on the source/drain region, the epitaxial film containing germanium and carbon and doped with phosphorus At the same time as the above steps, the pressure in the process chamber is maintained at at least about 100 Torr. Process conditions can be adjusted as described above.

The above description is a broad description of some of the features and technical advantages of the present invention. It will be appreciated by those skilled in the art that the specific embodiments disclosed may be readily utilized as a basis for the modification and design of other structures or processes within the scope of the invention. Those skilled in the art should also understand that such equivalent embodiments do not depart from the spirit and scope of the invention as defined by the appended claims.

Embodiments of the present invention generally provide a method of forming an epitaxial layer comprising germanium and carbon and doped with phosphorus. Other embodiments are directed to methods of making a transistor. In accordance with one or more embodiments, the process chamber pressure is at least about 100 Torr during the epitaxial deposition process. In particular embodiments, the pressure can be at least about 200 Torr or at least about 300 Torr.

As used herein, epitaxial deposition refers to the deposition of a single crystal layer on a substrate, so that the crystalline structure of the deposited layer conforms to the crystalline structure of the substrate. Therefore, the epitaxial layer or film is a single crystal layer or a film whose crystal structure conforms to the crystal structure of the substrate. The epitaxial layer is distinguished from the bulk substrate and the polycrystalline layer.

According to an embodiment of the invention, the substrate deposited by the epitaxial film is usually The substrate is ruthenium and it can be a patterned substrate. The patterned substrate is a substrate having an electronic feature formed on or within the surface of the substrate. The patterned substrate can comprise a single crystal surface and at least a second surface that is non-single crystalline, such as a polycrystalline or amorphous surface. The single crystal surface includes a bare substrate or a deposited single crystal layer, which is typically made of a material such as tantalum, niobium or tantalum carbon. The polycrystalline or amorphous surface may comprise a dielectric material such as an oxide or a nitride, specifically germanium oxide or tantalum nitride, and an amorphous germanium surface.

The tantalum carbon layer can be deposited in a suitable process chamber using an epitaxial process, such as Epi RP or Centura, available from Applied Materials, Santa Clara, California. Generally, the process chamber is maintained at a uniform temperature throughout the epitaxial process, however, some of the steps can be performed at different temperatures. The process chamber is maintained at a temperature between about 250 ° C and about 1000 ° C, such as between about 500 ° C and about 900 ° C. The appropriate temperature for performing the epitaxial process depends on the particular precursor used to deposit and/or etch the carbon and germanium containing materials, and can be determined by those skilled in the art. The process chamber is typically maintained at from about 0.1 Torr to about 600 Torr, and the pressure varies between the deposition step and the deposition step, but is generally maintained constant.

In the epitaxial deposition process, the substrate is exposed to a deposition gas to form an epitaxial layer on the surface of the single crystal while forming a polycrystalline layer on the second surface. The specific exposure time of the deposition process is determined by the exposure time of the etch process, as well as the particular precursor and temperature used in the process. Generally, the substrate is exposed to the deposition gas for a sufficient period of time to form a maximum thickness of the epitaxial layer and to form a minimum thickness of the polycrystalline layer, while the polycrystalline layer is deposited. The period can be easily removed by etching.

The deposition gas contains at least one helium source, one carrier gas, and one carbon source. In an alternative embodiment, the deposition gas can include at least one etchant, such as hydrogen chloride or chlorine.

The source of germanium is typically supplied to the process chamber at a rate of from about 5 sccm to about 500 sccm, for example, from about 10 sccm to about 300 sccm, and specifically from about 50 sccm to about 200 sccm, more specifically 100 sccm. Sources of ruthenium that can be used in deposition gases to deposit compounds containing ruthenium and carbon include, but are not limited to, decane, decane, and organodecane. The decane includes decane (SiH ₄ ) and a higher level of decane having the experimental formula of Si _x H _(2x+2) , such as dioxane (Si ₂ H ₆ ), trioxane (Si ₃ H ₈ ), and tetraoxane (Si). ₄ H ₁₀ ) and so on. Halogenated halogen includes a compound of the formula X' _y Si _x H _(2x+2-y) , wherein X'=F, Cl, Br or I, for example: hexachlorodioxane (Si ₂ Cl ₆ ), tetrachloro Oxane (SiCl ₄ ), dichlorodecane (Cl ₂ SiH ₂ ), and trichlorodecane (Cl ₃ SiH). The organodecane includes a compound having the formula R _y Si _x H _(2x+2-y) , wherein R = methyl, ethyl, propyl or butyl, such as methyl decane ((CH ₃ )SiH ₃ ), Dimethyldecane ((CH ₃ ) ₂ SiH ₂ ), ethyl decane ((CH ₃ CH ₂ )SiH ₃ ), methyldioxane ((CH ₃ )Si ₂ H ₅ ), dimethyldioxane (( CH ₃ ) ₂ Si ₂ H ₄ ) and hexamethyldioxane ((CH ₃ ) ₆ Si ₂ ).

The helium source is typically delivered to the process chamber with the carrier gas. The flow rate of the carrier gas is between about 1 slm (volume flow rate per unit time under standard conditions) ~ about 100 slm, for example about 5 slm to about 75 slm, more specifically about 10 slm to about 50 slm, for example about 25 slm . The carrier gas may include nitrogen (N ₂ ), hydrogen (H ₂ ), argon, helium, and combinations thereof. An inert carrier gas is preferred and includes nitrogen, argon, helium, and combinations thereof. The choice of carrier gas is based on the precursor and/or process temperatures used in the epitaxial process. The same carrier gas is typically used in each step. However, some embodiments may use different carrier gases in a particular step.

The carbon source provided to the process chamber in the step is accompanied by a helium source and a carrier gas to form a compound containing ruthenium and carbon, such as a ruthenium carbon material, and the rate at which the carbon source is supplied to the process chamber is generally from about 0.1 sccm to about 20 sccm, for example, From about 0.5 sccm to about 10 sccm, and more specifically from about 1 sccm to about 5 sccm, such as about 2 sccm. Carbon sources useful for depositing compounds containing ruthenium and carbon include, but are not limited to, hydrocarbons, olefins, alkynes that are organodecane, ethyl, propyl, and butyl. Such carbon sources include methyl decane (CH ₃ SiH ₃ ), dimethyl decane ((CH ₃ ) ₂ SiH ₂ ), trimethyl decane ((CH ₃ ) ₃ SiH), ethyl decane (CH ₃ CH _{2 )} SiH ₃ ), methane (CH ₄ ), ethylene (C ₂ H ₄ ), acetylene (C ₂ H ₂ ), propane (C ₃ H ₈ ), propylene (C ₃ H ₆ ), and the like. The epitaxial layer has a carbon concentration of from about 200 ppm to about 5 atomic percent, for example, from about 1 atomic % to about 3 atomic %, more specifically at least 2 atomic %, or at least About 1.5 atomic%. In one embodiment, the concentration of carbon in the epitaxial layer is graded. Preferably, the lower portion of the epitaxial layer has a higher carbon concentration relative to the upper portion. Alternatively, the helium source and the carbon source may be added to the process chamber along with the helium source and the carrier gas to form a compound containing ruthenium and carbon, such as ruthenium carbon.

The deposition process is over. In one example, the process chamber can be flushed with a purge gas or a carrier gas, and/or the process chamber can be evacuated using a vacuum pump. Clean gas and / or exhaust treatment will be excessive process gas, reaction By-products and other contaminants are removed. In another example, once the deposition process is complete, the etching process is then performed without the need to purge and/or vent the process chamber.

Etching

A selective etching process can be performed which removes portions of the epitaxial layer on the surface of the substrate. The etching process removes both epitaxial or single crystalline materials as well as amorphous or polycrystalline materials. The polycrystalline layer, if any, deposited on the surface of the substrate is removed at a faster rate than the epitaxial layer. The duration of the etching process is balanced with the duration of the deposition process to obtain a net deposition result of the desired region of the epitaxial layer selectively formed on the substrate. Thus, the net result of the deposition process and the etch process is the formation of germanium and carbon containing species that selectively and epitaxially grow while minimizing the growth of polycrystalline materials, if any.

The time during which the substrate is exposed to the etching gas during the etching process is from about 10 seconds to about 90 seconds, such as from about 20 seconds to 60 seconds, and more specifically from about 30 seconds to about 45 seconds. The etching gas includes at least one etchant and a carrier gas. The etchant is typically supplied to the process chamber at a rate of from about 10 sccm to about 700 sccm, such as from about 50 sccm to about 500 sccm. The etchant used in the etching gas may include chlorine (Cl ₂ ), hydrogen chloride (HCl), boron trichloride (BCl ₃ ), methyl chloride (CH ₃ Cl), carbon tetrachloride (CCl ₄ ), and chlorine fluoride. (ClF ₃ ) and combinations thereof. Preferably, chlorine or hydrogen chloride is used as an etchant.

The etchant is typically supplied to the process chamber along with the carrier gas. The flow rate of the carrier gas is from about 1 slm to about 100 slm, for example from about 5 slm to about 75 slm, more specifically from about 10 slm to about 50 slm, for example about 25 slm. The carrier gas typically includes nitrogen (N ₂ ), hydrogen (H ₂ ), argon, helium, and combinations thereof. In some embodiments, an inert carrier gas is preferred, including nitrogen, argon, helium, and combinations thereof. The carrier gas system is selected based on the temperature used in the particular precursor and/or epitaxial process.

The etching process is finished. In one example, the process chamber can be flushed with purge gas or carrier gas, and/or the process chamber can be evacuated using a vacuum pump. The scrubbing and/or exhaust treatment removes excess etching gases, reaction byproducts, and other contaminants. In another example, once the etching process is complete, the thickness of the epitaxial layer is then measured without the need to purge and/or vent the process chamber.

The thickness of the epitaxial layer and the polycrystalline layer can be measured. Once the predetermined thickness is reached, the epitaxial process is then stopped. However, once the predetermined thickness is not reached, the cycle is followed by a deposition process until the desired thickness is reached. The thickness of the epitaxial layer grown is from about 10 Å to about 2000 Å, such as from about 100 Å to about 1500 Å, more specifically from about 400 Å to about 1200 Å, for example about 800 Å. The deposited polycrystalline layer, if any, has a thickness ranging from one atomic layer to about 500 Å. The desired or predetermined thickness of the epitaxial germanium-containing and carbon layer or polycrystalline germanium-containing and carbon-containing layers is unique to a particular process system. In one example, the epitaxial layer can reach a predetermined thickness while the polycrystalline layer is too thick.

Doping exposure

During epitaxial deposition, the epitaxial layer is exposed to the dopant. Typical dopants include at least one dopant compound to provide an elemental dopant source such as boron, arsenic, phosphorus, gallium or aluminum. In a particular embodiment of the invention, the ruthenium and carbon containing compound is doped n-type, for example doped at a concentration of between about 10 ¹⁵ atoms/cm ³ (atoms per cubic centimeter) to about 10 ²¹ atoms/cm ³ of phosphorus and/or arsenic.

The dopant source is typically supplied to the process chamber. Sources of dopants may include hydrazine (AsH ₃ ), phosphine (PH ₃ ), and alkyl phosphines, for example, having the experimental formula R _x PH _(3-x) wherein R = methyl, ethyl, propyl or butyl, and x=1, 2 or 3. Alkylphosphines include trimethylphosphine ((CH ₃ ) ₃ P), dimethylphosphine ((CH ₃ ) ₂ PH), triethylphosphine ((CH ₃ CH ₂ ) ₃ P), and diethyl phosphine ( (CH ₃ CH ₂ ) ₂ PH).

A particular embodiment of the invention relates to the formation of an in situ phosphorus doped selective Si:C epitaxial layer at a high pressure in excess of 100 Torr. A high pressure of more than 100 Torr causes an increase in growth rate and an increase in the carbon concentration of substitution, as shown in Figure 1. The temperature at which the experiment was carried out and the flow rate of the ruthenium and carbon precursor and the carrier gas were maintained constant. In different experiments, the pressure was changed to 6 Torr, 100 Torr and 300 Torr. The results are shown in Figure 1. As shown in Figure 1, a higher pressure results in a higher substituted carbon concentration. More specifically, the sample produced under a pressure of 6 Torr has a carbon substitution of 0.8% while the other process conditions are kept constant; the sample produced under a pressure of 100 Torr has a substituted carbon of 1.1%; The sample produced under a pressure of 300 Torr had a substituted carbon of 1.4%.

According to an embodiment of the invention, in a suitable process example of selective Si:C epitaxy, the phosphorus concentration is greater than about 2 x 10 ²⁰ atoms/cm ³ , the carbon concentration is about 1.3 atomic %, and the substitution level is about 0.6. Atomic%. The process chamber can be maintained at a temperature of about 700 ° C, a pressure of about 300 Torr, a hydrogen carrier gas flow rate of 10 slm, a gas flow rate of a 200 sccm dichlorodecane source, and a HCl flow rate of 30 sccm. The flow rate of methyl decane (1% diluted in hydrogen) was 240 sccm, and the flow rate of phosphine (1% diluted in hydrogen) was 240 sccm. All of the process gas flows into the process chamber at the same time, and a carbon-containing ruthenium layer doped with phosphorus is formed on the substrate. Samples produced at higher pressures were observed to have higher HCl etch activity. Thus, in accordance with embodiments of the present invention, etching performed at a temperature at which HCl activity is weak (e.g., less than about 700 ° C) may employ a higher press. In the example of generating phosphorus doping, secondary ion mass spectrometer (SIMS) data shows that a pressure in excess of 100 Torr results in a phosphorus content greater than 2 x 10 ²⁰ atoms/cm ³ .

Processes of the above type can be used in a selective deposition process in which a deposition and etching gas system simultaneously flows into the chamber, resulting in a Si-C epitaxial film doped with phosphorus on the single crystal surface of the substrate, but on a dielectric surface. There is no growth on the top. The higher HCl activity at higher pressures allows the etching to proceed at lower temperatures, such as below about 700 °C.

The epitaxial film according to an embodiment of the present invention may be further annealed, for example, by a rapid thermal process such as rapid thermal annealing, rapid thermal processing, laser annealing, microsecond annealing, and/or spike annealing or flash annealing or a combination thereof. . The annealing temperature depends on the process used.

One or more embodiments of the present invention provide a method that is particularly useful for forming complementary metal oxide semiconductor (CMOS) integrated circuit components and will be described below. Other elements and applications are also within the scope of the invention. Figure 2 shows a partial cross-sectional view of a FET pair of a typical CMOS device. Element 100 includes The semiconductor substrate after forming a well provides a source/drain region, a gate dielectric layer, and a gate electrode of the NMOS device and the PMOS device. Element 100 can be formed by conventional semiconductor processes, such as growing a single crystal germanium and forming a shallow trench isolation structure by trench etching, and growing or depositing a dielectric in the trench opening. The detailed steps for forming such structures are well known to those skilled in the art and will not be described again herein.

Element 100 includes a semiconductor substrate 155 (eg, a germanium substrate) doped with a p-type material, a p-type epitaxial layer 165 on substrate 155, p-well regions 120 and n defined in epitaxial layer 165 A well region 150, an n-type transistor (NMOS FET) 110 defined in the p-type well region 120, and a p-type transistor (NMOS FET) 140 defined in the n-type well region 150. The first isolation region 158 electrically isolates the n-type transistor 110 and the p-type transistor 140. The second isolation region 160 electrically isolates the transistors 110, 140 from other semiconductor components on the substrate 155.

In accordance with one or more embodiments of the present invention, NMOS transistor 110 includes a gate electrode 122, a first source region 114, and a drain region 116. The thickness of the NMOS gate electrode 122 is variable and can be adjusted based on component performance considerations. The work function of the NMOS gate electrode 122 corresponds to the work function of the N-type element. The source and drain regions are n-type regions on opposite sides of the gate electrode 122. Channel region 118 is located between source region 114 and drain region 116. The gate dielectric layer 112 separates the channel region 118 from the gate electrode 122. The process for forming the NMOS gate electrode 122 and the dielectric layer is well known in the art and will not be described herein.

According to one or more embodiments, the PMOS transistor 140 includes a gate electrode The pole 152, the source region 144 and the drain region 146. The thickness of the PMOS gate electrode 152 is variable and can be adjusted based on component performance considerations. The work function of the PMOS gate electrode 152 corresponds to the work function of the N-type element. The source and drain regions are p-type regions on opposite sides of the gate electrode 152. Channel region 148 is located between source region 144 and drain region 146. Gate dielectric layer 142 separates channel region 148 from gate electrode 152. Dielectric layer 142 insulates gate electrode 152 from channel region 148. It should be understood that the structures of the transistors 110, 140 shown in "Fig. 2" and described above are merely exemplary, but various variations in materials and layers are also within the scope of the present invention.

Referring now to "Fig. 3", it is an additional detail showing the formation of the NMOS device 110 of the "Fig. 2" on the spacer, the source/drain region (e.g., a germanide layer), and the formation of an etch stop layer. . It should be understood that the PMOS device shown in FIG. 3 may contain similar spacers and layers whose size and/or composition may be modified to affect the induced stress in the channel of the NMOS device, as described below. However, for purposes of illustration, only NMOS elements are shown and described in detail.

"Picture 3" shows that the spacer 175 can be formed of a suitable dielectric material that is incorporated around the gate 119. Offset spacers 177 may also be disposed around each of the spacers 175. The process for forming the shape, size and thickness of the spacers 175, 177 is well known to those skilled in the art and will not be described again herein. A metal telluride layer 179 can be formed over the source region 114 and the drain region 116. The metal telluride layer 179 can be formed by a suitable process (eg, sputtering or physical vapor deposition [PVD]) and from a suitable metal, such as: Nickel, titanium or cobalt. The telluride layer 179 can diffuse to a portion of the lower surface. The height of the drain region 116 is indicated by arrow 181, which is the distance from the substrate surface 180 to the top end of the telluride layer 179. The faces 183 of the source and drain regions are shown as angled surfaces. As will be appreciated by those skilled in the art, the exemplary components described above can be modified to include source/drain or source/drain extensions having a Si:C epitaxial layer, which can be further Further modifications are made by the method of the invention.

Any reference to "an embodiment," "partial embodiment," or "one or more embodiments" in the specification means that a particular feature, structure, material, or feature is described in connection with the embodiment. In at least one embodiment of the invention. Therefore, such phrases as used in the specification are not necessarily referring to the embodiments. Furthermore, the particular features, structures, materials, or characteristics may be combined in one or more embodiments in a suitable manner. The order in which the above methods are described is not intended to be limiting, and the above methods may be performed in an out-of-sequence operation or omitted or added.

However, the present invention has been described above by way of a preferred embodiment, and is not intended to limit the present invention. Any modification and refinement made by those skilled in the art without departing from the spirit and scope of the present invention should still belong to the technology of the present invention. category.

100‧‧‧ components

110,140‧‧‧Optoelectronics

112, 142‧‧ dielectric layer

114,144‧‧‧ source area

116, 146‧‧ ‧ bungee area

118,148‧‧‧Channel area

119‧‧‧ gate

120,150‧‧‧ Well Area

122,152‧‧‧gate electrode

155‧‧‧Substrate

158,160‧‧‧Isolated area

165‧‧‧矽/Eplayer

175‧‧ ‧ spacers

177‧‧‧ spacers

179‧‧‧ Telluride layer

180‧‧‧ surface

181‧‧‧ arrow

183‧‧‧ face

In order to make the above-mentioned features of the present invention more obvious and understandable, it can be explained with reference to the reference embodiment, and a part thereof is illustrated as a drawing. It is to be understood that the specific embodiments of the present invention are not intended to limit the spirit and scope of the invention. The equivalent embodiment is decorated.

1 is a high-resolution X-ray diffraction spectrum (HR-XRD spectra) of an epitaxial layer containing carbon and germanium under high pressure; and FIG. 2 is a diagram showing field effect according to an embodiment of the present invention. A cross-sectional view of the transistor pair; and FIG. 3, a cross-sectional view of the PMOS field effect transistor of FIG. 2, with additional layers formed on the component.

Claims (11)

A method of forming an epitaxial layer containing tantalum and carbon on a substrate, comprising placing a substrate in a process chamber, wherein the substrate comprises a single crystal surface and at least a second surface, the first The two surface is selected from the group consisting of an amorphous surface, a polycrystalline surface, and a combination of the above surfaces, wherein an epitaxial layer is formed on the surface of the single crystal, and a polycrystalline layer is formed on the second surface; The substrate is exposed to a source of germanium, a source of carbon and a source of phosphorus, and at the same time maintaining a pressure in the process chamber above about 200 Torr to form a doped phosphorus on at least a portion of the substrate a silicon epitaxial film (Si: C epitaxial film); and exposing the substrate to an etching gas including hydrogen chloride (HCl) to further process the substrate, wherein the temperature in the process chamber is less than or equal to about 700 °C. The method of claim 1, wherein the pressure in the process chamber is maintained at at least about 300 Torr. The method of claim 1, wherein the epitaxial film is formed to contain a substitutional carbon, and the substituted carbon is at least about 50% of the total carbon content in the epitaxial film. The method of claim 1, wherein the phosphorus source comprises phosphine, and the concentration of phosphorus in the epitaxial film is at least about 10 ²⁰ atoms/cm ³ . A method of forming an epitaxial layer containing tantalum and carbon on a substrate, comprising: placing a substrate in a process chamber, the substrate comprising a single crystal surface and at least a second surface, the first The surface is selected from an amorphous surface, a polycrystalline surface, and a combination of the above surfaces; the substrate is exposed to a source of germanium, a source of carbon, a source of phosphorus, and an etching source including hydrogen chloride (HCl), and simultaneously Maintaining the pressure in the process chamber above about 200 Torr and maintaining the temperature below about 700 ° C to form a phosphorus-doped bismuth carbon epitaxial film on the surface of the single crystal without growing on the surface On the second surface. The method of claim 5, wherein the second surface comprises a dielectric surface. The method of claim 5, wherein the concentration of phosphorus in the tantalum carbon epitaxial film formed is greater than about 10 ²⁰ atoms/cm ³ . The method of claim 1, wherein the tantalum carbon epitaxial film is deposited in a manufacturing process of a transistor process, the process comprising: Forming a gate dielectric layer on a substrate in a process chamber; forming a gate electrode on the gate dielectric layer; forming a source on an opposite side of the gate electrode on the substrate a drain region defining a channel region between the source/drain regions; and depositing the epitaxial film directly on the source/drain regions, the epitaxial film containing germanium and carbon It is doped with phosphorus. The method of claim 8 wherein the pressure is maintained at at least about 300 Torr. The method of claim 8, wherein the temperature in the process chamber is maintained at less than or equal to about 700 °C. The method of claim 8, wherein the epitaxial film is formed to contain a substitutional carbon, and the substituted carbon is at least about 50% of the total carbon content in the epitaxial film.